1. Field of the Invention
The present invention relates to a television tuner which receives television signals using a smart antenna.
2. Description of the Prior Art
In television broadcasting, each broadcaster may use different transmitting points. In this case, for a television signal to be received at a receiving point, a receiver must be set so as to receive a desired channel signal and the directivity of the antenna must be adjusted to the transmitting point side of the receiving channel.
A receiver having a smart antenna whose directivity can be statically varied by an electrical signal has been known where the directivity of the smart antenna is automatically varied to all directions to search for a direction in which the state of a received television signal is good (for example, see JP-A No.298226/1999).
Recently, the present inventor has proposed a television tuner which uses a smart antenna as mentioned above to receive television signals where the smart antenna is controlled to change receiving channels as appropriate as follows: the smart antenna directivity is varied to different directions, the receiving condition in each direction is detected and channels on which the receiving condition is good and the corresponding smart antenna receiving directions are correlated to each other and stored in sequence. This type of television tuner is convenient because such smart antenna receiving directions are automatically stored for all receiving channels when an auto scan is performed to set channels for receiving television signals.
However, the above television tuner has the following problem: each time the state of a received signal is good on a receiving channel, the corresponding receiving direction of the smart antenna is stored, so it takes too much time to perform scanning for all receiving channels. Particularly when there are many receiving channels on which signals can be received, this problem is so serious that the user may feel irritated or uncomfortable.